Failing to pull down Prime Minister Manmohan SIngh's government in a confidence vote over the Indo-US Nuclear deal, the Communist Party of India-Marxist (CPI-M) Wednesday sacked the country's first communist speaker from the party.

The 79-year-old barrister and ten-time MP, Somnath Chatterjee, was also the first Bengali speaker of the Indian parliament. The CPI(M)'s decision was also the first of its kind in India where a party severed its links with a person in the high chair of the speaker.

The CPI(M) accused Chatterjee of violating party discipline by not resigning from his post despite a party directive to do so.

"The politburo has unanimously decided to expel Somnath Chatterjee from the membership of the party with immediate effect," said politburo member MK Pandhe.

Chatterjee was the focal point of a raging controversy in the past fortnight after his party withdrew support from the United Progressive Alliance (UPA) government in New Delhi.

He was put under intense pressure from the CPI-M to resign as the Lok Sabha Speaker. CPI-M wanted him to toe the party line, but he insisted on remaining in the post of the Speaker, maintaining that he was above party politics.

"We (Communists) have to abide by party rules. The party will severe all connections with those who do not follow party diktats. We cannot keep him as speaker. Mr (Somnath) Chatterjee might have acted according to the Indian Constitution, but our party has its own constitution and decisions are taken as per party rules," said Biman Bose, Left Front chairman and his colleague in the party for the last 50 years.

However, former attorney general and noted jurist, Soli Sorabjee clarified that despite the expulsion, Chatterjee still remained the Speaker of the Lok Sabha.

"The speaker was elected by the House. He was not elected as a nominee of any particular political party. His expulsion from the party has nothing to do with his continuation as the speaker. He can be removed only if he wants to resign himself or has to be voted out," Sorabjee said.

Amid allegations of buying MPs from all sides, the Congress-party led UPA government in New Delhi won the trust vote Tuesday.